Stannous alkylcatecholates



Patented Jan. 8, 1952 ITEDf E-s QFFICE I YSTANNOUS ALKYLCATECHOLATESGeorge E. P. Smith, Jr., Akron, Ohio, assignor-to.

' The Firestone Tire & Rubber Company, Akron, I :1" E 1 1 Y Ohio, acorporation of Ohio No Drawing.

' This invention relatesto stannous salts of alkylcatechols. Thesecompounds may contain one or more alkyl groups. Each alkyl group maycontain up to twelve or more carbon atoms. The compounds are valuable asrubber. stabilizers. Many ofthe alkylcatechols are relatively insolubliii'water andthrefore the stannous .alkylcatecholates usually cannot beprepared by the methods of preparing unsubstituted stannous catecholatein which purely aqueous reaction mixturesar'e employed. The stannousalkylcatecholates are usually made in solutions which are formedentirely or only partially of organic solvents, e. g. alcohol or alcoholand water.

The invention includes, for example, the stannous salts ofp-methylcatechol, p-ethylcatechol...

. that they may be formed by difierent methods as illustrated inExamples 1 and 2. They contain one molecular weight of tin for eachmolecular weight of the alkylcatechol and are therefore referred to asnormal salts.

The examples illustrate the preparation of certain of the compounds ofthis invention.

EXAMPLE 1 stannous p-tert-butylcatecholate One hundred grams (0.6 mole)of p-tertbutylcatechol was dissolved in 300 m1. ethanol. One hundredfifty grams (0.67 mole) of stannous chloride dihydrate was added withshaking. It dissolved almost completely. The reaction mixture waschilled in an ice bath and stirred mechanically while there was droppedinto it 55 grams of sodium hydroxide (1.38 mole) dissolved. in 225 ml.of water. Fifty milliliters of Water and 50 ml. of ethanol were added asthe mixture became thick. Then 75 ml. additional water was added forthinning. The reaction mixture was filtered, washed with water andethanol, and then dried in air at about 35 C. Yield 180 grams.

Application August 10, 1948. Serial No. 43.5w y 5 claims. (c1. ecu-.429)Q EXAMPLE 2 stannous p-tert-butylcatecholate an'aqueousjsolutioncontaining 5.1 grams oi sodiuni hydroxide. A blood red solution. was 10btain'edjto' which was added slowly and with stirring 13.6 grams ofstannous chloride dihydrate in cc. of water. The red color disappearedas a pure white precipitate was formed. The precipitate was separatedand dried and was found to be identical with that prepared in Example 1.

EXAMPLE 3 Stannous 4-tert-butyZ-3-methylcatech0late Nine and five-tenthsgrams of 4-tert-butyl-3- methylcatechol and 11.9 grams of stannouschloride dihydrate were dissolved in 200 ml. of methanol. To theresulting solution a solution of 4.2 grams of sodium hydroxide in 200ml. of 25 per cent methanol were added slowly while stirring. Theresulting precipitate was filtered, washed with alcohol-water and thenwith water. Yield 12.6 grams.

EXAMPLE 4 Simmons dz'butylcatecholate Twenty-two and two-tenths grams ofdibutylcatechol (.1 mole) and 22.6 grams of stannous chloride dihydratewere dissolved in 500 ml. of ethyl alcohol. A solution of 8.0 grams ofsodium hydroxide in 150 ml. of 40 per cent alcohol was added slowlyduring stirring. The resulting precipitate was filtered. It was washedwith alcohol and then with alcohol-water. The yield was 23.0 grams ofdried stannous dibutylcatecholate.

EXAMPLE 5 stannous octylcatecholate Nine and five-tenths grams ofoctylcatechol was dissolved in 150 ml. of methanol. Nine and six-tenthsgrams of stannous chloride dihydrate was then dissolved in the resultingsolution. To this was added a solution of 3.4 grams of sodium hydroxidein m1. of 30 per cent methanol. The precipitate was filtered withsuction, washed with methanol-water and then with water, and then dried.Yield 13.3 grams.

EXAMPLE 6 stannous octyl-el-methylcateoholate Seven and five-tenthsgrams of octyl-4-methylcatechol was dissolved in 150 ml. of methanol andthen 7.2 grams of stannous chloride dihydrate was added and dissolved. Asolution of 2.54 grams ofsodiu'm hydroxide in lOQ of 25 per centmethanol was added slowly during stirring. The precipitate was filtered,washed once withmethanol-water and twice with water. product weighed 9.6grams.

EXAMPLE -.7 j stannous heptylcatecholate Six and five-tenths grams ofheptylcatechol and 71.1 grams of stannous chloride dihydrate were;

dissolved in 150 m1. of methanol. To this a solution of 2.5 grams ofsodium hydroxide in 100 ml. of 25 per cent methanol v'qas added. Theproduct was filtered with suction, washed withwateroh l. nd, then withwater. When dry it weighed 9.0 grams;

EXAMPLE 8 Stannous 4,5-dimethylcatecholate Six and fivertenths gramsof4.-5-dimethylcatech01 was dissolved in 100 ml., of 30 per cent methanoland 10.6 grams of stannous chloride dihydrate was added. To theresulting solution a solution of 3.76" grams of sodium hydroxide. in 100ml. of water was added slowly duringstirring.

The dried REFERENCES CITED The-following references are of record in'the file of this. patent:

UNITED STATES PATENTS Number Name Date 2,252,663 Reifi Aug. 12, 19412310;449 Lightbown et al Feb. 9;.1943 2,445,727 Kinzinger Aug.;25, 194

OTHER REFERENCES Majima etaL; Ber. deutsch. chem. Ges." vol. 46 (1913),page 4083. I

Beilstein, Handbuch der' Org. Chemie, 4th ed, vol. 6, 1st. Supp; (1931),page 456. I

Spath et a1., "Ber. deutsch. chem. Ges. vol..60 (1927), page 1888.

Beilstein, Handbuch der Org. Chemief, 4th ed, vol. 6.2nd Supp, (1944)page892.

1. STANNOUS ALKYLCATECHOLATES.